1. Field of the Invention
The invention relates in general to a method and circuit for testing a multi-chip package (MCP).
2. Description of the Related Art
Along with the multi-chip packaging technology develops, an integrated circuit (IC) provider, especially for mobile-phone applications, tends to incorporate several chips, including a known-good-die (KGD) Flash memory, a SRAM memory and a controller etc. provided by different suppliers, into a multi-chip package (MCP) so as to reduce the cost of IC products.
Normally, when a memory chip including several bare dies, is supplied to the IC provider, the die supplier will test all the bare dies to guarantee their good quality and reliability, such as at least 90% dies are good. Accordingly, the IC provider can package the known good-dies together with other IC chips. However, one trouble often confuses the die supplier: during the package process, if any damage happens to cause a failure to the whole package device, there is no way for the IC provider to know whether the memory chip produced by the die supplier or other chips have defects to cause a failure of the finished package. As a result, the IC provider has to deliver the whole package device to respective chip supplier to test which chip of the multi-chip package is damaged, thereby increasing complication of produce delivery. Therefore, there is a need to test the memory chip, which is easiest to be damaged, after the package is finished in order to guarantee the memory chip is good for the IC provider.